Early and late outcomes of ambulatory counter pulsation devices as a bridge to heart transplantation

Introduction: The intravascular ventricular assist device is a newly developed ambulatory and portable counter pulsation heart assist system. The purpose of this study is to compare the early and late outcomes of counter pulsation devices between iVAS and axillary intra-aortic balloon pump (IABP) as a bridge to heart transplantation. Methods: This is a single-center, retrospective study. Between April 2016 and March 2020, 24 patients underwent iVAS implantation (Group A), and 73 patients underwent axillary IABP (Group B) as a bridge to heart transplantation. We reviewed and compared perioperative data, as well as late survival outcomes. Results: There were no significant differences in baseline characteristics. All patients in Group A and 97.3% of patients in Group B were able to ambulate and participate in physical therapy(p=0.28). There were no in-hospital deaths in the two groups. The median duration of device support in Group A was significantly longer than in Group B(A:37.0days vs B:15.0days,p<0.01). After the US Food and Drug Administration approved the discharge of patients with an iVAS, four patients (4/14,28.6%) were discharged home with the device. The success rate of bridge to transplantation was not significantly different between the groups (A:21/24, 87.5% vs B:68/73, 93.2%, p=0.40). Late survival after heart transplantation also did not differ between the groups (A:85.7% at 3-year vs B:94.0% at 3-year, log rank=0.22). Conclusions: Both iVAS and axillary IABP showed comparable success rates of bridge to transplantation and late survival after transplantation. The mobile design of iVAS facilitated excellent ambulatory capability and enabled patients to be discharged home.